My 2 cents:
To all those who frown upon mercenary runs:
When you go to the grocery store to stock up on the food that keeps you alive, do you frown upon the fact that you are spending money on food rather than growing it yourself? Do you frown upon the act of paying for your electricity bill rather than generating your own? Do you frown upon driving a car that you had no part whatsoever in building?
How is this any different?
Some people don't have the time to spend 10 hours a day throwing bodies at titan for a week with bad pugs, or duty finder noobs trying to learn the ropes. Some of these might be crafters and gatherers capable of generating many runs worth of gil in the same amount of time they would otherwise spend learning the mechanics of this fight, let alone finding a Full Party of equally capable and competent players. Why should these players waste countless hours of their time (and money) trying to kill titan when they can pay a group to kill it for them in under 30 minutes?
Such a transaction should not be frowned upon it should be encouraged. The master crafter who spends his days honing his technique may not have the experience to kill titan nor a group of friends willing to carry him through it. However, he may have an excess of gil and if he is willing to peddle his wares in exchange for gil, why should he not be allowed to pay a group of mercenarys to kill a mob for his relic? It is a win/win situation. The raiders who never craft are payed by a crafter for killing a mob he is not capable of, meanwhile these same raiders will likely spend that hard earned gil purchasing goods being sold by this crafter, that they in turn are incapable of crafting.
This is equivalent exchange in every sense of the word. No one is being ripped off. Each person provides either a good or a service in exchange for gil. The crafters provide goods in the form of items and the mercenaries provide a service in the form of a boss mob kill. Everyone walks away from the transaction happy and with a smile on their face. What exactly is wrong with this notion of efficiency? Nothing.
If you still think this is wrong, then I am left to wonder, who are you to judge what others choose to do with their hard earned gil?